River lengths in Croatia determined from a topographic map at a scale of 1:25,000

This study presents methodologically consistent length measurements of rivers with a total 40 kilometres or more in the Republic Croatia. These were performed by vectorising river channels from topographic map at scale 1:25,000. Contemporary orthophoto maps used as additional cartographic sources for verification. The approaches to determine starting and ending points rivers, i.e. mouths confluences, have been explained their spatial coordinates listed. results showed that terms length, 21 this differed available official data less than 5%. Considerable differences found where significant engineering works had carried out channelize divert flow, well Adriatic Basin there methodological determining mouth, large lowland changes channel planform are common due natural dynamics interventions. Moreover, research revealed longest Croatian river, its source, confluence, both banks situated entirely within territory Croatia, is Karašica River, 148 km.